Displaying 2 results from an estimated 2 matches for "d58511".
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58511
2019 Feb 26
3
Dealing with illegal operand mappings in RegBankSelect
...with an example.
> Let say we have:
> = inst a(bank1)
> And inst only accepts bank2.
> Are you saying that you lie by saying that bank1 is legal in that case?
> If so, why applyMapping would do any rewriting since this is legal.
Yes. It’s what happens here: https://reviews.llvm.org/D58511 <https://reviews.llvm.org/D58511>
For extract_vector_elt, the indirect register index type must be an SGPR. I’ve implemented the mapping as just copying the original source bank and allowing applyMapping to deal with it. There might be cases that aren’t correctly being rewritten, but I haven...
2019 Feb 21
2
Dealing with illegal operand mappings in RegBankSelect
Hi,
Some operations on AMDGPU require operands which must be in a register bank that is impossible to copy from another. The operation needs to be rewritten in a complex way to avoid the illegal copy.
Currently if I correctly report the required register banks in the operand mapping, RegBankSelect happily inserts the illegal copies, somehow concluding they are cheap (I would at least hope